Grip for a Golf Club Shaft

ABSTRACT

A grip for a shaft for a golf club, the golf club comprising a head provided at a first end of the shaft and a second end of the shaft corresponding to the hand placement area on which the grip is formed, and a method for forming such a grip are disclosed. A grip comprises a sleeve of heat-shrinkable material adapted to be inserted over the second end and an under listing positioned along the second end, wherein the sleeve is inserted over the second end and the under listing positioned thereon, and shrinks onto the second end upon heat application. A method for forming a grip comprises positioning an under listing along the second end, inserting a sleeve of heat-shrinkable material over the second end and the under listing positioned thereon, applying heat to the sleeve such that the sleeve shrinks onto the second end. A golf club shaft comprising a first end and a second end, with a grip at the second end, said grip comprising an under listing positioned along the second end and an elongate hollow cylindrical heat shrinkable sleeve that is open on each end that is slidably inserted over the second end onto which the under listing has been positioned, whereby the grip is fixed onto the second end by applying heat to the sleeve to cause the sleeve to shrink onto the second end.

FIELD OF THE INVENTION

The present invention relates to a grip for a golf club shaft, a method for forming such grip, and a golf club shaft with such a grip formed thereon.

BACKGROUND OF THE INVENTION

Golf started in the early sixteenth century in Scotland. In the early days of golf and up through the early to mid 1900's, golf putters, which are a type of golf club comprised of a shaft with an upper hand placement portion known as a grip and a lower portion which is connected to a head that strikes a golf ball, have been gripped with a simple leather wrap to offer a gripping surface for wooden shafts and, thereafter, for metal shafts. The leather wrap offered not only a gripping surface, but also provided golfers with a feel for the weight of the putter head as the leather wrap grip was lightweight, thin, and directly connected to the shaft to offer maximum feel for making a golf stroke. In addition to golf putters, such a leather wrap was also used on the grip for other golf clubs.

Over time, with the introduction of new materials to golf equipment, the material for grips for a golf club shaft transitioned from leather to rubber. In addition, grips were made in various shapes and sizes offering golfers a choice in design. Recently, the popularity of over-sized grips for golf putters in particular has risen due to golfers' perceived benefit that such grips offered in eliminating the use of the hands in a golf stroke. Specifically, it is believed that an over-sized grip limits use of the hands which would not disrupt the angle of the putter head when making a stroke so that the face of the putter and ball meet at the desired angle to roll the ball along the golfer's intended line.

However, an over-sized grip for a golf putter has a number of drawbacks. First, the over-sized grip adds weight to the upper portion of the shaft away from the putter head located at the lower portion of the shaft. This disturbs the balance and feel of the putter head for the golfer, which are critical for a golfer in order to control the putter head. If a golfer cannot feel the weight of the putter head when making a stroke, it is difficult for the golfer to control the putter head in a way to roll the ball down the golfer's intended line.

Secondly, the size of an over-sized grip numbs the feel of the hands in a way as to deaden the feel of the ball striking the face of the putter head. This also reduces the sound of the putter head striking the ball. Both feel and sound are important for a golfer to determine if the ball struck the putter head directly in the center of the face of the putter head. Without the proper feel and sound, a golfer has a much harder time knowing if he or she has made solid contact with the ball during the stroke.

Thirdly, the size of an over-sized grip limits the golfer's sense of touch in his or her hand and fingers which adversely affects the golfer's ability to gauge and judge distance when putting. Specifically, golfers use their hands and fingers to relay a sense of touch to the brain. With this sense of touch impaired, it is more difficult for golfers to know how hard to strike the ball to achieve the desired distance of roll. To overcome the shortcomings of an over-sized grip for a golf club shaft in general and for putters in particular, there exists a need to aid golfers in feeling the weight of the head at the lower end of the shaft (i.e., opposite end from the grip), increase the awareness of feel in the hands of a golfer and improve the sound heard by a golfer when the ball strikes the face of the face of the golf club head and increase the sense of touch in the hands and fingers for controlling the distance the ball is rolled off the face of the golf club head.

SUMMARY OF THE INVENTION

A first aspect of the invention provides a grip for a shaft of a golf club, the golf club comprising a head provided at a first end of the shaft and a grip provided at a second end of the shaft, the grip comprising an elongate hollow cylindrical sleeve of heat-shrinkable material that is open on each end and adapted to be slidably inserted over the second end of the shaft and an under listing positioned along the second end of the shaft, wherein the sleeve is slidably inserted over the second end of the shaft and the under listing positioned thereon, and shrinks onto the second end of the shaft upon the application of heat. Preferably, the length of the elongate hollow cylindrical sleeve of heat-shrinkable material is approximately ten inches and the under listing provides a substantially flat, non-curved and non-circular surface for a golfer to rest the thumbs when gripping the grip. Preferably, the under listing is adhered onto the second end of the shaft.

A second aspect of the invention provides a method for forming a grip for a shaft of a golf club comprising a head provided at a first end of the shaft and a grip provided at a second end of the shaft, the method comprising positioning an under listing along the second end of the shaft, slidably inserting an elongate hollow cylindrical sleeve of heat shrinkable material that is open on each end over the second end of the shaft and the under listing positioned thereon, applying heat to the sleeve such that the sleeve shrinks onto the second end of the shaft. Preferably, the under listing is adhered onto the second end of the shaft before slidably inserting the sleeve over the second end of the shaft.

Further advantageous aspects of the invention will become apparent to those of ordinary skill in the art upon review of the following description of the embodiments of the invention and with reference to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is now described by way of example and with reference to the accompanying drawings:

FIG. 1 is a schematic representation of a typical golf club;

FIG. 2 is a view of one end of a sleeve for a grip for a golf club shaft positioned above a second end of the shaft in accordance with an embodiment of the present invention;

FIG. 3(a) is a perspective view of an under listing for a grip for a golf club in accordance with an embodiment of the present invention;

FIG. 3(b) is a side view of an under listing positioned on a second end of a golf club shaft in accordance with an embodiment of the present invention;

FIG. 4(a) is a side view of a sleeve positioned to the side of a second end of a shaft with an under listing positioned on the shaft for a grip for a golf club in accordance with an embodiment of the present invention;

FIG. 4(b) is a side view of a grip for a golf club shaft formed at the second end of the shaft after the heat shrinkable sleeve has been slidably inserted over the second end of the shaft with an under listing positioned thereon and shrunk, with the application of heat, onto the second end of the shaft in accordance with an embodiment of the present invention; and

FIG. 4(c) is an end view of a grip for a golf club shaft in accordance with an embodiment of the present invention.

FIG. 4(d) is a cross-sectional view of a grip for a golf club shaft in accordance with all embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows, generally indicated as 10, a typical golf club. The golf club 10 comprises a shaft 12 having a head 14 at a first end 16 and a second end 18 which corresponds to the hand placement area of golf club 10. Second end 18 has a lower portion toward the first end 16 and head 14 and an upper portion that ends at butt 19. The shaft 12 is usually made from metal or a composite material, especially a carbon fiber based composite material commonly referred to as graphite. The head 14 may take a variety of different shapes and sizes depending on the intended use for the club 10. The head 14 is typically made of metal, wood, or a carbon-based composite material such as graphite.

Referring now to FIG. 2, there is shown a sleeve 20 which, when slidably inserted over the second end 18 of shaft 12 of golf club 10 as indicated by the arrow, forms a grip for a golf club shaft. Sleeve 20 has an elongate hollow cylindrical shape and is made of heat-shrinkable material. Preferably, the heat-shrinkable material comprises a heat-shrinkable plastic. The preferred plastic is polyethylene terephthalate (PET), although alternative plastics such as polyvinylchloride (PVC), neoprene, or a polyolefin such as polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), or polybutane-1 (PB-1).

Sleeve 20 is open on each end and may be formed by any convenient method, for example wrapping a sheet of suitable material on itself and welding or seaming its edges together to form an elongate hollow cylindrical tube shape. Sleeve 20 can also be formed by first extruding the raw material (pushing raw material for sleeve 20 through a die of the desired cross-section of sleeve 20) followed by expanding the resulting extruded material by blowing air or another suitable gas into the extruded material for the desired length. The length of sleeve 20 may be less than, substantially as long as, or longer than the length of a typical hand placement area of a golf club. Preferably, sleeve 20 is approximately ten inches.

Sleeve 20 is comprised of a thin-walled type material that is sufficiently thin and pliable during the heating stage to substantially conform to the shape of the second end 18 of shaft 12. The inner diameter of sleeve 20 preferably is larger than the width or diameter of second end 18 so as to allow sleeve 20 to be easily slidably inserted over second end 18 of shaft 12.

Referring now to FIGS. 3(a) and 3(b), there is shown a preferred embodiment of under listing 30 which, when placed along second end 18 of shaft 12, provides a substantially flat, non-curved and non-circular surface for a golfer to rest the thumbs when gripping shaft 12. Under listing 30 is an integral structure comprised of a top longitudinal surface 32, a bottom longitudinal surface 34, a first vertical lateral surface 36 and a second vertical lateral surface 38 each extending between longitudinal surfaces 32 and 34, and an upper vertical transverse surface 40 and a lower vertical transverse surface 42 each extending between longitudinal surfaces 32 and 34. Preferably, under listing 30 has a substantially rectangular cross section. Further, under listing 30 preferably has a substantially flat top longitudinal surface 32 and substantially concave bottom longitudinal surface 34 that conforms to the shape of shaft 12. Although shown in the preferred embodiment depicted in FIGS. 3(a) and 3(b) as having a rectangular cross section resulting from each of top longitudinal surface 32 and bottom longitudinal surface 34 being flat, the cross sectional shape of under listing 30 can take a variety of different shapes depending on the intended use for club 10 or the preference of the golfer, with top longitudinal surface 32 being flat or round and bottom longitudinal surface 34 being one of flat or formed to conform to the shape of shaft 12)

Under listing 30 is a thin structure with a preferred width, corresponding to the distance separating top longitudinal surface 32 and bottom longitudinal surface 34, of preferably approximately 9 mils to approximately 13 mils. The width W of under listing 30 preferably is sized to cover approximately one quarter (or ninety degrees) of the external surface (circumference) of second end 18 of shaft 12. Under listing 30 can be formed by any convenient method known in the art such as injection molding, extrusion, or three-dimensional (3D) printing.

Preferably, bottom longitudinal surface 34 of under listing 30 has adhesive characteristics so that when under listing 30 is positioned along second end 18 of shaft 12, bottom longitudinal surface 34 of under listing 30 adheres onto the exterior surface of second end 18 of shaft 12. The imparting of adhesive characteristics to bottom longitudinal surface 34 of under listing 30 can be performed using one of many known techniques in the art, such as the application of a liquid glue along the length of bottom longitudinal surface 34 or, preferably, the use of double-sided tape. Preferably, the adhesive characteristics of bottom longitudinal surface 34 are maintained before positioning along second end 18 of shaft 12 by covering surface 34 with a pull-away paper or plastic strip that, when removed, exposes the adhesive bottom longitudinal surface 34.

Referring now to FIGS. 4(a), 4(b), 4(c), and 4(d), there is shown a grip 40 for a golf club 10 formed on second end 18 of shaft 12 which corresponds to the hand placement area of golf club 10. Grip 40 is formed on second end 18 of shaft 12 by first positioning under listing 30 along second end 18 of shaft 12. Under listing 30 is positioned along the portion of the exterior surface of second end 18 of shaft 12 that corresponds to the portion of second end 18 onto which a golfer would rest his or her thumbs when gripping shaft 12. Preferably, such positioning of under listing 30 imparts a substantially flat, non-curved and non-circular surface on second end 18 of shaft 12 as shown in FIGS. 4(c) and 4(d), which enables a golfer to rest the thumbs when gripping grip 40. Preferably, under listing 30 is positioned along second end 18 of shaft 12 by adhering bottom longitudinal surface 34 onto the exterior surface of second end 18 of shaft 12.

After positioning under listing 30 along second end 18 of shaft 12, sleeve 20 is slidably inserted over second end 18 of shaft 12 so that it overlays the entire length L of under listing 30. Sleeve 20 can be equal to or greater in length than under listing 30. Preferably, sleeve 20 is longer than under listing 30 by approximately one-half inch with approximately one-quarter inch of sleeve 20 extending beyond the lower portion of second end 18 and approximately one-quarter inch of sleeve 20 extending beyond the upper portion of second end 18 that is pushed into the interior of shaft 12 at butt 19. With sleeve 20 thus positioned, heat is then applied to the external surface of sleeve 20. The heat can be applied from one of many known heat sources known in the art such as a heat lamp, heat gun, or hair dryer. The heat is applied all around the exterior surface of second end 18 of shaft 12 until sleeve 20 shrinks onto the exterior surface of second end 18 of shaft 12 and conforms to the shape of shaft 12 so that sleeve 20 holds itself in position on second end 18 of shaft 12 during use of club 10 by the shrink-wrapping process. A preferred method of applying the heat is the use of a back-and-forth motion along the length of sleeve 20 at a distance from sleeve 20 of between approximately one-half to approximately one inch while rotating shaft 12 so as to heat the entire length of sleeve 20 around the entire exterior surface of second end 18.

Grip 40 is sufficiently thin so that when a golfer grips second end 18 of shaft 12 at grip 40, the golfer can feel the weight of the head at the first end 16 of the shaft, increasing the awareness of feel in the hands of the golfer, with less deadening of sound when head 14 strikes the ball, compared to typical prior art thicker grips.

The invention is not limited to the embodiments descried herein which may be modified or varied without departing from the scope of the invention. 

1. A grip for a golf club shaft, the shaft comprising a head at a first end and a second end corresponding to the hand placement area of the golf club, the grip comprising: a. an elongate hollow cylindrical heat shrinkable sleeve that is open on each end and adapted to be slidably inserted over the second end of a shaft; b. an under listing, wherein the under listing is shaped from the group consisting of (i) a substantially flat, non-curved and non-circular surface with a rectangular cross section, and (ii) a substantially flat top longitudinal surface and a substantially concave bottom longitudinal surface that conforms to the shape of the shaft; c. wherein the under listing is positioned along the second end of the shaft; d. wherein the sleeve is slidably inserted over the second end of the shaft and the under listing positioned thereon; e. wherein the sleeve shrinks onto the second end of the shaft upon the application of heat to the sleeve; and f. wherein at least a portion of the outer surface of the grip is substantially flat.
 2. A grip as claimed in claim 1, wherein the under listing is adhered onto the second end of the shaft.
 3. A grip as claimed in claim 1, wherein the sleeve is made from one or more materials selected from the group consisting of polyethylene terephthalate, polyvinylchloride, neoprene, or a polyolefin such as polyethylene, polypropylene, polymethylpentene, and polybutane-1.
 4. A grip as claimed in claim 1, wherein the length of the sleeve is approximately ten inches.
 5. (canceled)
 6. (canceled)
 7. (canceled)
 8. A grip as claimed in claim 1, wherein the width of the under listing covers approximately one quarter of the external surface of the second end of the shaft.
 9. (canceled)
 10. (canceled)
 11. (canceled)
 12. (canceled)
 13. (canceled)
 14. (canceled)
 15. (canceled)
 16. (canceled)
 17. A golf club shaft comprising: a. a first end and a second end corresponding to the hand placement area of the golf club; b. a head at the first end; c. a grip at the second end of the shaft, said grip comprising an under listing positioned along the second end of the shaft and an elongate hollow cylindrical heat shrinkable sleeve that is open on each end that is slidably inserted over the second end of the shaft onto which the under listing has been positioned; d. wherein the grip is fixed onto the second end of the shaft by applying heat to the sleeve to cause the sleeve to shrink onto the second end of the shaft; e. wherein the under listing is shaped from the group consisting of (i) a substantially flat, non-curved and non-circular surface with a rectangular cross section, and (ii) a substantially flat top longitudinal surface and a substantially concave bottom longitudinal surface that conforms to the shape of the shaft; and f. wherein at least a portion of the outer surface of the grip is substantially flat.
 18. A golf club shaft as claimed in claim 17 wherein the under listing is adhered onto the second end of the shaft.
 19. (canceled)
 20. (canceled) 